President Carter is to arrive in Tehran Saturday for meetings with Shah Mohammed Reza Pahlavi and King Hussein of Jordan at which the main focus of discussion is expected to be the latest moves for Middle East peace, but Iranian dissidents are hoping Carter will also press his human rights policy on Iran.

Carter's visit, following Hussein's arrival today, comes amid indication of apparent attempts by the Iranian government to discredit political opposition with Watergate-style dirty tricks. The latest of these is an open letter bitterly attacking Carter in the name of the newly revived National Front, which opposes the shah.

A Front leader charged today that the letter, distributed clandestinely to foreign news agencies last night, was a fake put out by the government. He said the Front welcomes Carter's visit and supports his human rights policy.

"We have no animosity whatsoever against President Carter's visit and supports his human rights policy.

"We have no animosity whatsoever against President Carter's visit and supports his human rights policy.

"We hater's visit and supports his human rights policy.

"We have no animosity whatsoever against President Carter's visit," Shahpour Bakhtiar said. "We have always supported Mr. Carter's campaign for human rights." He added that he hoped Carter would raise the subject here as he did in Warsaw.

Carter is due to arrive at Mehrabad airport west of Tehran about 7 a.m. EST and be driven in an open-topped motorcade along with the shah to Saadabad Palace in northern Tehran, where the two leaderw will hold talks. The motorcade plans have surprised some diplomats here and worried security men.

Diplomatic sources said the talks would cover oil matters, nuclear energy cooperation, the security of the strategic Persian Gulf, U.S. arms sales to Iran, the war in the Horn of Africa and Middle East peace. The discussion will basically be a follow-up to talks held during the shah's visit to Washington last month, according to Information Minister Dariush Homayoun.

Carter will also receive a message left here by Domali President Mohannad Siad Barre, who appealed during a news conference in Tehran earlier this week for U.S. military aid in his country's war with Ethiopia.

The shah will pursue a proposal he made in Washington on a new way to fund development of alternative energy sources, officials said. The shah plan involves creating international energy bonds that would be guaranteed by industrialized countries and subscribed by oil-producing states, thereby redirecting surplus petrodollars into energy ventures to help both groups. The plan has yet to be studied, but Carter is said to be interested. On nuclear energy, officials hope some progress can be made toward a bilateral protocol that would permit U.S. reactor sales to Iran.

After their talks, the shah will host a banquet at his Niavaran Palace residence for President and Mrs. Carter and King Hussein. The Carters are expected to be back at the guest palace before midnight and will apparently see in the New Year privately.

The President is scheduled to meet King Husseing early the next morning before leaving for New Delhi on the third stop of this six-nation tour.

Scores of plainclothes agents of the Iranian secret police, Savak, have been stationed at the Hilton Hotel, where reporters and most members of the presidential party are staying. Men armed with light submachine guns patrol every floor.

The security threat was underscored by the bombing Wednesday of an American-sponsored language school in downtown Tehran. The blast damaged the four-story building and blew out windows of nearby apartments and businesses. A policeman standing outside was cut by flying glass.

Responsiblity for the bombing was claimed by a previously unknown guerrilla group, but observers expressed doubts about the authenticity of the claim.

Diplomatic sources also were not ruling out the possibility that the bombing was staged to discredit opposition to the shah.

Other recent incidents in Iran, which some diplomatic sources believe were staged by government agents, have included an anti-American demonstration in front of a U.S. wrestling team at a Tehran sports complex and the burning of carpets at a synagogue in the central Iranian city of Isfahan. Sources said the government apparently wanted to put an anti-American or pro-radical Palestinian face on dissent in Iran.

The disclaimed National Front letter accused Carter of promoting "a dirty plot for the surrender of Arab and Moslem rights to the Zionist state throught the treachery of the old traitor Anwar Sadat." It also called Carter "the father of the human killer neutron bomb" and condemned his visit to Iran.